/*
    * Copyright 2020 the original author or authors.
    *
    * Licensed under the Apache License, Version 2.0 (the "License");
    * you may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
    *
    *      http://www.apache.org/licenses/LICENSE-2.0
    *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package org.bremersee.actuator.security.authentication;
  
  import java.util.ArrayList;
  import java.util.List;
  import java.util.Set;
  import java.util.TreeSet;
  import java.util.stream.Collectors;
  import javax.validation.constraints.NotEmpty;
  import javax.validation.constraints.NotNull;
  import lombok.EqualsAndHashCode;
  import lombok.Getter;
  import lombok.Setter;
  import lombok.ToString;
  import org.bremersee.security.authentication.AccessExpressionUtils;
  import org.bremersee.security.authentication.AutoSecurityMode;
  import org.bremersee.security.authentication.ClientCredentialsFlowProperties;
  import org.bremersee.security.core.AuthorityConstants;
  import org.springframework.boot.context.properties.ConfigurationProperties;
  import org.springframework.util.StringUtils;
  import org.springframework.validation.annotation.Validated;
  
  /**
   * Actuator authentication and authorization properties.
   *
   * @author Christian Bremer
   */
  @ConfigurationProperties(prefix = "bremersee.actuator.auth")
  @Getter
  @Setter
  @ToString
  @EqualsAndHashCode
  @Validated
  public class ActuatorAuthProperties {
  
    /**
     * Specifies the behaviour of the actuator security auto configuration.
     */
    @NotNull
    private AutoSecurityMode enable = AutoSecurityMode.OTHER;
  
    /**
     * The order of the actuator security auto configuration.
     */
    private int order = 61;
  
    /**
     * Specifies whether cors should be enabled for the actuator endpoints or not.
     */
    private boolean enableCors = true;
  
    /**
     * A list with unauthenticated actuator endpoints.
     */
    @NotNull
    private List<Class<?>> unauthenticatedEndpoints = new ArrayList<>();
  
    /**
     * The roles which can write to protected actuator endpoints. The role names normally start with {@code ROLE_}.
     */
    @NotNull
    private List<String> adminRoles = new ArrayList<>();
  
    /**
     * The roles which can read protected actuator endpoints. The role names normally start with {@code ROLE_}.
     */
    @NotNull
    private List<String> roles = new ArrayList<>();
  
    /**
     * The IP addresses which can access protected actuator endpoints without authentication.
     */
    @NotNull
    private List<String> ipAddresses = new ArrayList<>();
  
    /**
     * The JWK uri.
     */
    private String jwkSetUri;
  
    /**
     * The JWS algorithm
     */
    @NotEmpty
   private String jwsAlgorithm = "RS256";
 
   /**
    * The issuer uri.
    */
   private String issuerUri;
 
   /**
    * The json path in the JWT to the roles.
    */
   @NotEmpty
   private String rolesJsonPath = "$.realm_access.roles";
 
   /**
    * Specifies whether the roles value is a list (json array) or a simple string.
    */
   private boolean rolesValueList = true;
 
   /**
    * The role value separator to use if the role value is a simple string.
    */
   @NotNull
   private String rolesValueSeparator = " ";
 
   /**
    * The role prefix to add.
    */
   @NotNull
   private String rolePrefix = "ROLE_";
 
   /**
    * The json path in the JWT to the user name.
    */
   @NotEmpty
   private String nameJsonPath = "$.preferred_username";
 
   /**
    * The password flow properties for the actuator endpoints.
    */
   @NotNull
   private ActuatorPasswordFlow passwordFlow = new ActuatorPasswordFlow();
 
   /**
    * Gets unauthenticated endpoints or defaults (these are the health and info endpoints).
    *
    * @return the unauthenticated endpoints
    */
   @NotNull
   public List<Class<?>> unauthenticatedEndpointsOrDefaults() {
     if (unauthenticatedEndpoints.isEmpty()) {
       unauthenticatedEndpoints.add(
           org.springframework.boot.actuate.health.HealthEndpoint.class);
       unauthenticatedEndpoints.add(
           org.springframework.boot.actuate.info.InfoEndpoint.class);
     }
     return unauthenticatedEndpoints;
   }
 
   /**
    * Roles or defaults.
    *
    * @return the roles
    */
   @NotNull
   public Set<String> rolesOrDefaults() {
     final TreeSet<String> roleSet = new TreeSet<>(roles);
     if (roleSet.isEmpty()) {
       roleSet.add(AuthorityConstants.ACTUATOR_ROLE_NAME);
       roleSet.add(AuthorityConstants.ACTUATOR_ADMIN_ROLE_NAME);
       roleSet.add(AuthorityConstants.ADMIN_ROLE_NAME);
     }
     return roleSet.stream()
         .map(this::ensureRolePrefix)
         .collect(Collectors.toSet());
   }
 
   /**
    * Admin roles or defaults.
    *
    * @return the admin roles
    */
   @NotNull
   public Set<String> adminRolesOrDefaults() {
     final TreeSet<String> roleSet = new TreeSet<>(adminRoles);
     if (roleSet.isEmpty()) {
       roleSet.add(AuthorityConstants.ACTUATOR_ADMIN_ROLE_NAME);
       roleSet.add(AuthorityConstants.ADMIN_ROLE_NAME);
     }
     return roleSet.stream()
         .map(this::ensureRolePrefix)
         .collect(Collectors.toSet());
   }
 
   /**
    * Build access expression (SpEL) for actuator endpoints.
    *
    * @return the access expression (SpEL) for actuator endpoints
    */
   @NotNull
   public String buildAccessExpression() {
     return AccessExpressionUtils.hasAuthorityOrIpAddressExpr(
         rolesOrDefaults(), null, ipAddresses);
   }
 
   /**
    * Build access expression (SpEL) for admin actuator endpoints.
    *
    * @return the access expression (SpEL) for admin actuator endpoints
    */
   @NotNull
   public String buildAdminAccessExpression() {
     return AccessExpressionUtils.hasAuthorityOrIpAddressExpr(adminRolesOrDefaults(), null, null);
   }
 
   /**
    * Ensure role prefix.
    *
    * @param role the role
    * @return the role with prefix
    */
   @NotNull
   public String ensureRolePrefix(@NotNull String role) {
     final String prefix = rolePrefix.trim();
     return StringUtils.hasText(prefix) && role.startsWith(prefix) ? role : prefix + role;
   }
 
   /**
    * OAuth2 password flow configuration properties.
    */
   @Getter
   @Setter
   @ToString(exclude = {"clientSecret"})
   @EqualsAndHashCode(exclude = {"clientSecret"})
   public static class ActuatorPasswordFlow implements ClientCredentialsFlowProperties {
 
     private String tokenEndpoint;
 
     private String clientId;
 
     private String clientSecret;
   }
 }